Electronic compass relay



Patented Aug. 30, 1949 sures raramr oral-cs rtGiianted "underthe act of March 3, .1883, as amended April 30, 1928; 870 0. 7537) *5 Claims.

with pcsiticnei instruments "capable er preset g only extrem'ely weak torque, such as '0' passes, gyrm scenes, or other similar ts the proper operation of which would be impaired ii an appre ci elbleloadwere p whereas,

Accordingly, it is object-oi the present invention to provide acon-trol system having electronic means responsive to the movement of the positional instrument for producing an output signal for controlling the mechanism to be oriented.

Another object is to provide a control system having photosensitive means, responsive to light variations due to movement of the positional instrument, for producing a signal to be used to automatically determine the operation of the mechanism to be controlled.

Other objects and advantages of the invention will become more fully apparent from the following description taken in connection with the annexed drawings, which illustrates a preferred embodiment, and wherein:

Fig. 1 is a section of the mechanism of the present invention taken on the line l-| of Fig. 2, the said mechanism being shown connected to the other elements of the system.

Fig. 2 shows a section of the mechanism taken on the line 2-2 of Fig. 1.

Fig. 3 is a sectional view taken along line 3-3 of Fig. 1; and

Fig. 4 shows a section taken along the line 4-4 of Fig. 1.

Referring now to the drawings, wherein like reference characters designate like or corresponding parts throughout the several views, there is shown in Fig. 1 a tubular housing ll of nonmagnetic material, preferably aluminum, provided with a partition l2 having a. pair of slots l3 therein, slots I3 being sealed by windows l4 held in place by flanges IS.

The upper portion of the housing I l comprises a cover plate iii to which is secured a reflector mounting bracket l1 having a reflector t8 mo1mt- 'ed thereon, reflector :Hl being designed to 'refiect parallel rays of light from light source i3. Also secured to'cover iplate I 6 is amoimti-ng bracket 2| having "a phototube :22, or other light sensitive 'device, mounted Within housing 11 between plate 18 and partrtion I2 is a light tight dividing partition 23 to which are secured a paire'f mas'lcing plates 24 and 25. Masking plate 24 is mounted in the portion containing light source I-9 and has a slit 205 therein which serves to transmit a narrow beam of 'l-ig-htconsisting of parallel light rays. Masking plate 25 is mounted in the portion containing phototube 22 and supports a lens 21 which serves to focus any light rays directed thereat on the sensitive elements of lpho tetube 22.

The lower portion of housing H comprises a compass card chamber #28 in which is mounted a vertical pivot 29 which pivotally supports compass card 3|, said card being provided with needle magnets 32 to produce the required compass effect and quadrature spaced tabs 33 for damping. The outer margin 34 and the area within spiral 35, developed centrally of compass card 3| is coated with or formed of opaque non-reflecting material, while the area 36 between spiral 35 and outer margin 34 is coated with or formed of light reflecting material, for example silvered. Chamber 28 is hermetically sealed and may be filled, or partially filled, with some satisfactory transparent liquid to damp the motion of card 3|. Housing H is provided with a mounting flange 3'! so that the entire device may be mounted in a gimbal.

Extending from the control elements of phototube 22 through cover plate iii are a pair of conductors 38' and 39 which are connected to an amplifier 4| through a battery 42 in a conventional manner. The output of amplifier 4| is fed to a controlled mechanism 43, which may be any mechanical or electrical device for effecting a desired orientation.

In operation, light from source I9 is reflected from reflector l8 as parallel rays through the slit 26 down to compass card 3|, and is reflected from area 36 of card 3| to lens 21 where it is focused on phototube 22. As the area within spiral 35 is non-reflecting, any rotational movement of card 31 relative to slit 26 will vary the width and quanta of the light beam reaching lens 21 and phototube 22 by blanking out a portion thereof, and thereby vary the response of phototube 22. The varying amount of light received by phototube 22 is transformed into electrical impulses which are amplified by amplifier 4| and then fed.

to the controlled mechanism 43 which may be an automatic steering mechanism. Thus, if the heading of a ship, or any other movable object on which the invention is mounted, is altered, compass card 3! will turn with respect to the ship and thereby. .vary the quanta of light reaching phototube 22. As spiral 35 moves in relation to slit 26, it operates in effect as a linear cam blanking out a portion of the beam reflected from card 3| in a linear functional manner. Any other desired functional variation may be achieved, by altering the configuration of the blanking design on card 3|, but it is preferable that this variation purposes without the payment of any royalties thereon or therefor.

What is claimed is:

1. In an electronic control system, the combination comprising: a housing; a source of light within said housing; means for reflecting a portion of said light in parallel rays; a plate having a narrow slit therein mounted in the path of said rays for producing a narrow beam; a rotatable compass card positioned in the path of said beam, said card having a light reflecting portion and a light blanking spiral portion for varying the quanta of light from said beam reflected by said card as a linear function of angular displacement of said card; a photo-emissive tube within 4 said housing; a lens mounted in the path of the reflected light for converging said reflected light on said tube; and means for amplifying the output of said tube, said means being adapted to be connected to a controllable device.

2. In an electronic control system, the combination comprising: a source of lightymeans for forming a narrow beam of light from said source; a rotatable compass card positioned in the path of said beam, said card having a light reflecting portion and a light blanking spiral portion for varying the quanta of light from said beam reflected by said card as a linear function of angular displacement of said card; light sensitive means positioned in the path of the reflected light; and means for amplifying the output of said light sensitive means.

3. The combination according to claim 2, and means positioned between said card and said light sensitive means for converging said reflected light on said light sensitive means.

4. In an electronic control system, the combination comprising: a source of light; a rotatable compass card positioned in the path of the light, said card having a light reflecting portion and a light blanking spiral portion for varying the quanta of light reflected by said card as a linear function of angular displacement of said card; and light sensitive means positioned in the path of the reflected light.

5. In combination with a controllable device, a source of light, a rotatable compass card positioned in the path of said light for reflecting a portion thereof, said card having a light blanking portion thereon for varying the quanta of light reflected by said card in accordance with the angular displacement thereof, and light sensitive means positioned in thepath of the reflected light, said means being connected to said device.

ROBERT C. HARRINGTON, JR.

No references cited. 

